The accuracy with which automated manufacturing equipment is able to work parts depends largely on the quality of the location and orientation information used with the equipment. For example, with poor location and/or orientation information about a part, the most state of the art manufacturing equipment will only be able to work the part in a marginal manner. Conversely, with precise location and orientation information, a marginal piece of equipment may be able to perform well.
Automated manufacturing processes requiring a moderate amount of accuracy do not call for particular part location and orientation information beyond knowing that the part has been positioned in a standard place. For these processes, the accuracy of standard part positioning allows part working with sufficient accuracy. In these processes, for example, a part to be worked can be placed in a standard location in or near the applicable automated machine, for example by abutting a predetermined edge of the part with a predetermined edge of a work platform and the machine can be programmed to work the part in that standard location. In processes requiring only moderate accuracy, standard part placement and machine operation are precise enough to achieve desired results.
Automated manufacturing processes requiring a high level of accuracy call for part locating and/or orienting after the part has been positioned. Some processes require automated machinery to work parts with a very high degree of accuracy. For example, very high accuracy is required where interchangeable hole patterns are being used. Interchangeable hole patterns are those made in product parts likely to be interchanged during the life of the product. For example, while most other parts of aircraft may not require changing, it may be determined that a particular door typically requires replacement at least once during the life of the aircraft. In this example, the mating characteristics of the door and the door mounting location of the plane must lie within tighter than standard tolerances.
Although parts of aircraft are generally manufactured at or about the same time and often in the same plant, an aircraft and a replacement part therefor may be manufactured at different plants and far apart in time. For example, an aircraft manufacturer may outsource replacement part manufacture to a supplier. Although various manufacturing inaccuracies in a process repeatedly performed in the same place and time may cancel each other out or aggregate within acceptable limits, a part made decades later at a different location is less likely to have these benefits. For example, manufacturing inaccuracies in formation of a first part are more likely to have inaccuracies that correspond to complimentary inaccuracies made in a second part on the same machine on the same day.
Although many part locating and orienting processes are adequate, it is generally desirable to have an improved system and method that takes into account at least some of the issues discussed above, as well as possibly other issues.